1. Technical Field
The present invention relates to a conductive paste composition and a method for producing a multilayer ceramic capacitor using the same, and more particularly, to a conductive paste composition including a glass composition having specific compositions in a conductive paste for an inner electrode to increase firing shrinkage starting temperature and discharging an inhibitor to a dielectric layer during a firing process to improve dielectric characteristics while being fired together with a dielectric, and a method for producing a multilayer ceramic capacitor using the same.
2. Description of the Related Art
As a demand for small, light, and multi-functional electric and electronic products is rapidly increased, a demand for a small and high-capacity multilayer ceramic capacitor used therefor is also increased accordingly. Therefore, a dielectric layer and an inner electrode layer used for the multilayer ceramic capacitor are gradually thin and highly stacked.
In order to manufacture the multilayer ceramic capacitor including an ultra-thin dielectric layer, a dielectric composition that can be sintered at low temperature should be used. The connection of the inner electrode is a very important factor in implementing the capacitance of the multilayer ceramic capacitor. Generally, a nickel electrode layer used as the inner electrode is sintered at a lower temperature by several hundred ° C. than a sintering temperature of a dielectric, such that the sintering shrinkage discordance between the dielectric layer and the inner electrode occurs when the firing temperature is too high and the aggregation phenomenon of the inner electrode is serious to lower the capacitance of the ceramic capacitor and to increase a short ratio. Therefore, in order to prevent the phenomenon, it is preferable to sinter the nickel inner electrode and the dielectric layer at a low temperature of 1100° C. under the reducing atmosphere.
Instead of using BaO—CaO—SiO2-based glass frit or BaSiO3-based mixing powders that are used as a sintering aid for producing a multilayer ceramic capacitor according to the related art while accelerating the low-temperature firing, a method for performing low-temperature firing, or the like, by newly preparing a glass composition for low-temperature firing and adding it to a dielectric has been actively researched and developed. Since the sintering aid using the BaO—CaO—SiO2-based glass frit or BaSiO3-based mixing powders has a high melting point of 1200° C., it is difficult to promote the sintering at a low temperature of 1150° C. or less and a liquid-phase formation is rapidly performed at high temperature, thereby causing a problem in that the sintering temperature range for producing the multilayer ceramic capacitor is very limited.
Therefore, in the method for producing a multilayer ceramic capacitor in order to secure the excellent electrode connection and the dielectric characteristics, the low-temperature firing is inevitable. Generally, the low-temperature characteristics are implemented by adding the glass composition for low-temperature firing to the dielectric layer but a technology of improving the dielectric characteristics during the firing process by introducing the glass composition for low-temperature firing into the conductive paste composition for the inner electrode has not yet been implemented until now.